Engineer s or surveyor s instrument



(No Model.)

2 SheetsSheet 1. C. L. BERGER. ENGINEERYS 0R SURVBYORS INSTRUMENT.

Patented Mar. 2, 1897.

(No Model.) 2 Sheets-Sheet 2.

G. L. BERGER. BNGINEERS 0R SURVEYORS INSTRUMENT.

No. 578,052. Patented Mar. 2,.1 897.

UNITED STATES PATENT OFFICE.

CHRISTIAN L. BERGER, OF BOSTON, MASSACHUSETTS.

ENGINEERS OR SURVEYORS INSTRUMENT.

SPECIFICATION forming part of Letters Patent No. 578,052, dated March 2, 1897.

Application filed pt m 28, 1896- Serial No. 607,160. (No model.)

To all whom it may concern.-

' Be it known that I, CHRISTIAN L. BERGER, of Boston, in the county of Suffolk and State of Massachusetts, have in vented an Improvementin Engineers or Surveyors Instruments, of which the following description, inconnection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

One object of my invention is to provide.

means for readily adjusting engineers and surveyors instruments to the required line of collimation for near distances Without the necessity of the usual appliances to the tele-- scope.

According to my invention I simply move the telescope after it has been adjusted for long ranges bodily to one side or the other parallel to itself a distance corresponding with the error of collimation found to exist by any known method, as, for instance, the sighting of a near object. Moving the instrument laterally bodily so that it becomes more or less eccentric to the vertical center of the instrument is equivalent to materially changing the base-line for near objects, while at the same time it is practically invariable for distant objects, inasmuch as infinite lines from a point are considered parallel, even though, as a matter of fact, they may diverge more or less.

Another object of my invention is to simplify the eyepiece, or, more properly speaking, the means of mounting the same, so that fewer parts than before accomplish the desired result and, moreover, do this much more effectually.

A further object had in view is the provision of a guard or protector for the vertical circle and provision of a Vernier so located and formed as to make it feasible to use the instrument in extremely narrow and confined places, as, for instance, in mine-surveying.

Further improvements and advantages of my present invention will be made apparent in the course of the following detailed description.

In the accompanying drawings, illustrative of the preferred embodiment of my invention, Figure 1 is a side elevation of a portion of a surveyors transit embodying my invention. Fig. 2 is a top plan view of Fig. 1, the telescope and its connected parts being removed, and shows one means of moving the telescope and standards bodily to one side. Fig. 3 is a central vertical section on line 3 3,- Fig. 2. Figs. 4 and 5 show, respectively, in side elevation and horizontal section a modified means for moving the telescope to one side of its center. Fig. 6 is a fragmentary view showin g in side elevation and partly in section another modification for the purpose of moving the telescope bodily to one side. Figs. 7 and 8 are respectively a side elevation and a longitudinal section of the eyepiece; and Fig. 9 is a central horizontal cross-section taken on the line 9 9, Fig. 1, showing my improved vertical circle, Vernier, and guard.

The base A, plate A, standards B, and telescope O, mounted on a horizontal axis D, the latter provided with the usual circle E and removable, if desired, from its bearings F by means of latch-plates G, may be and are all of any usual or preferred construction.

In correctly collimating a telescope it is Well known that the usual practice is to adjust the cross-wires for long ranges by means of capstan-headed screws usually provided therefor; but the required adjustment of these wires to eifect the correction of the error of collimation for near distances is a laborious and delicate task, requiring experience and skill and necessitating as Well a considerable manipulation of the instrument and waste .of time. This adjustment for collimation for near distances is all the more important because as a rule when once made it is usually final and need not be repeated in the field use of the instrument.

According to my invention I have entirely done away with the necessity of all this usual trouble in connection with short distances, and at the same time I haveinvented ameans for correctly collimating an instrument which renders the same absolutely perfect.

In order that my invention may be better understood, it may be remarked that, as is well known, a slight change of base in viewing a distant object, as a star, for instance, does not affect the direction at which the star is viewed, for the reason that the distance being relatively infinite the lines from one end of a reasonable terrestrial base and from the other end thereof are parallel. However, this does not hold true of objects at a short distance from the said base, but the angle of direction of these objects, such, for instance, as the corner-line of a house near by, is radically changed by moving along a base-line. Bearing this point in mind, it will be seen that the direction of the distant object may be considered constant and that the line of collimation, having been adjusted and corrected for this distant object, may then be disregarded in further collimatin the instrument, and that the error of collimation in viewing the near object is the only one that need be taken account of for the present purpose. Accordingly I take advantage of this fact and instead of moving the cross-wires of the telescope or providing other suitable means to do it I move the telescope itself bodily to one side of its vertical center of rotation such a distance that the resulting eccentricity of the entire telescope as it is swung around on its horizontal base corrects the error of collimation for near distances or, in other words, taken in connection with the above-mentioned primary collimation for long distances, produces the correct collimation of the instrument for all distances.

Referring to Figs. 2 and 3 more particularly, it will be seen that I have provided the base-plate A with a central boss a, preferably circular and herein shown as provided with fixed studs or bearing-posts a. The standards are herein shown as connected at their base by an integral piece or casting B. This casting is centrally apertured at I), this aperture being oblong, the shorter diameter thereof fitting snugly onto the circular boss (0 and extending transversely of the connection B. At the elongated ends of the aperture 1) setscrews b are provided, adapted to bear against the posts a. It will thus be seen that by loosening one set-screw Z) and tightening the opposite one the entire upper supporting portion of the telescope, and also the telescope, may be shifted laterally over the base-plate, and this lateral movement may be adjusted wit-h the utmost nicety. In fact, it is possible by the construction just described to adjust the telescope laterally with more precision and exactness than is ordinarily possible in moving the cross-wires for said purpose, as has been hitherto practiced. Having prop- 'erly adjusted the standards and telescope by means of the set-screws, as described, the standards are rigidly and permanently fixed in position by suitable fastening-screws, (indicated in dotted lines at 12 I do not-restrict this feature of my invention to the means already described, inasmuch as I believe myself to be broadly the inventor of thus laterally moving the telescope bodily parallel to itself for the purpose of collimating the instrument, and various other expedients for accomplishing the same movement may be resorted to.

In Figs. t and 5 I have shown the standards B as connected by means of a plate B which is slotted, as at 12 to receive the guide-screws Z)", the plate being moved laterally as desired by means of set-screws 1), operating through brackets b on the base-plate A against lugs 12 on the connection B In Fig. 6 I have shown the standards B as hinged at one side by suitable means, as by means of a capstan-screw bioperatin g through a lug b on the standard, and provided with hemispherical portions D fitting correspondingly-shaped recesses in the lug 1), thereby permitting a free hinging or turning movement of the parts, while at the same time maintaining firmness and accuracy of movement. At the opposite side of the standards a screw I), raised and lowered by means of a nut b, operating between two lugs I), is shown for the purpose of raising and lowering that side of the standards and thereby turning the standards on their opposite hinged portion as a pivot, so as to throw the telescope bodily over to one side or the other, as desired.

Viewing Figs. 7 and 8, II designates the eyepiece, adapted to fit snugly within the adjacent rearend II of the main tube of the telescope. A slow-motion focusingadjustment is provided for this eyepiece by means of a spiral groove or focusing-thread 72, formed in the eyepiece, to cooperate with the stud h, projecting from the inner side of the telescopetube.

Itis quite essential that the eyepiece should fit snugly and accurately within the tube H, but on account of the constant use of the eyepiece and its constant movement's back and forth within the tube II it has been found in practice extremely difficult to secure the fine adjustment necessary, and accordingly it is the usual practice to mount an intermediate tube between the tubes H and II, this v intermediate tube having a spiral slot and the eyepiece a stud to cooperate therewith, and the-interm ediate tube being screwed into and nicely adjusted within or on the main telescope-tube I-I. According to my invention, however, I have made it possible to omit this intermediate tube. I have prolonged the tube 11, as shown at 7L2, andhave slitted the same with two or more saw-cuts 7L so as to provide aspring-tongue h, which bears constantly 011 the eyepiece II. The extended bearing 7L2, taken in connection with the spring-tongue 7L", maintains the parts in perfectly steady and unvarying relation and at the same time affords a smooth motion to the eyepiece. The stud h is threaded and may be adjusted to fit accurately into the groove to impart motion to the eyepiece.

In mine-surveying it frequently happens that loose earth and matter from overhead drops on the instrument, and this proves disastrous in case the vertical graduated circle becomes damaged, as it is apt to, being the highest and most prominent portion of the instrument. Accordingly I have provided a guard K concentric with the graduated circle E and an overhanging flange 7c, '(see Fig. 9,) which practically incloses the circle,this guard or protector having considerable strength and being supported by a number of arms and braces 7c. The guard K is secured to the standard B, preferably adj ustably, by means of the set-screws 10 operating against a stud 10 as shown in Fig. 1, and the circle E turns freely within the guard or protector.

It is a further feature of my invention to mount on the guard K a Vernier K adjacent the eyepiece of the telescope, a counterbalancing weighted portion K being preferably provided on the guard opposite the Vernier in order to maintain the accuracy of balance of the instrument. The purpose of locating this Vernier as shown is to enable the instrument to be used with greater facility in minesurveying and other narrow and awkward positions Where it is impossible for the operator to place himself in such a position that he can read a vernier located as is usual in these instruments.

To make it still further possible for the operator to read the vernier K from his position at the eyepiece, I have arranged the graduations on the circle and the Vernier obliquely to the plane of the circle, as is shown in Fig. 9, so that the operator can readily read the angle by simply moving his position very slightly to the left of the eyepiece.

Many modifications in form, proportion, and arrangement of parts may be resorted to without departing from the spirit and scope of my invention.

Having fully described my invention, what I claim, and desire to secure by Letters Patent, isj 1. A surveyors or engineers instrument,

having its telescope mounted for horizontal.

pivotal movement relatively to its base, and means to adjust said telescope eccentrically to the center of said pivotal movement, said means moving the whole telescope bodily and simultaneously over parallel to itself, to correct the error of collimation for short distances, substantially as described.

2. A surveyors or engineers instrument, having its telescope mounted on a base-plate for horizontal pivotal movement relatively to its base, and means to bodilyadj ust said telescope and its bearings on said base-plate, substantially as described.

3. In a surveyors or engineers instrument, having a telescope, a base-plate, and standards supporting said telescope, a base on said base-plate and pivotally movable on the base, means to move said standards laterally relatively to said base-plate, said means including set-screws to accurately position said standards in the desired adjustment, substantially as described.

4. A surveyors or engineers instrument, comprising a telescope, a base-plate, standards supporting said telescope on said baseplate, and a connection between the lower ends of said standards, said connection having a central oblong aperture provided with a set-screw at either end thereof and adapted to fit over a boss provided on said base-plate, said set-screws being adapted to cooperate with said boss to shift the standards and telescope laterally relatively to the base-plate, substantially as described.

5. A surveyors or engineers instrument having a telescope, standards therefor, a connection at the lower end of said standards, said connection being provided with a central oblong aperture, set-screws at either end of said aperture, a base-plate having a central circular boss at its upper side adapted to fit snugly within said aperture and posts fixed in said boss and adapted to cooperate with said set-screws for the purpose of laterally adjusting said standards and telescope relatively to said base-plate, substantially as described.

6. A telescope having its main tube adjacent the eyepiece provided with an integral extension, as h said extension having a plurality of saw-cuts therein to thereby provide a spring tongue or portion, directly in the body or main telescope-tube, and having an eyepiece adapted to fit within said tube directly against said extension as a bearing and to be held snugly therein by said spring extension as h said extension havin a 111-.

rality of saw-cuts'therein, to thereby provide a spring tongue or portion directly in the body or main telescope-tube, and an eyepiece adapted to fit within said tube directly against said extension as a bearing and to be held snugly by said spring tongue or portion, said eyepiece being provided with an exterior focusing-thread, and said extension having a screw to cooperate with said focusingthread, substantially as described.

8. In an engineers or surveyors instrument, the combination with a telescope, its supports, and vertical circle, of a circular guard for said circle, said guard being concentric therewith and having a peripheral flange overhanging said circle as aprotection therefor, and a Vernier mounted at the extreme rear side of said guard adjacent the normal position of the eyepiece of the telescope, substantially as described.

9. In an engineers or surveyors instrument, the combination with a telescope, its supports and vertical circle, of a circular guard for said circle, said guard being concentric therewith and having a peripheral flange overhanging said circle as a protection therefor, and a Vernier mounted at the extreme rear side of said guard adjacent the normal position of the eyepiece of the telescope, said Vernier and the graduations of said circle being disposed in a plane oblique to the general direction of said circle, sub stantially as described.

10. In an engineers or surveyors instrument, the combination with a telescope, its supports and vertical circle, of a circular guard for said circle, said guard being concentric therewith and having a peripheral flange overhanging said circle as a protection therefor, and a Vernier mounted at the extreme rear side of said guard adjacent the normal position of the eyepiece of the telescope, said Vernier and the graduations of said circle being disposed in a plane oblique to the general direction of said circle, and

said guard having means to adjust the same relatively to the standards of the instrument, substantially as described.

In testimony whereof I have signed my 15 name to this specification in the presence of two subscribing Witnesses.

CHRISTIAN L. BERGER.

Witnesses: GEO. H. MAXWELL, JoHN O. EDWARDS. 

